3.5L M30 engine

Discussion in 'E9 General Discussion' started by Belgiumbarry, Dec 23, 2018.

  1. Belgiumbarry

    Belgiumbarry Well-Known Member

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    somebody presented me a complete '86 3.5L M30 … and i'm interested to have a spare for eventually my 01/70 blue coupe who has still his '69 2.8L engine with famous head …. i could overhaul that engine and have time... engine is already 5 years out of "a" car …. for a project that never came. It has the manual flywheel .

    but what is the average value for such engine ? when you ask sellers they ALL have low mileage and come from a rear ended wreck…. :D

    Can we check something visual on seller's site ? and i do not mean compression test etc.... because i would at least soak the pistons with diesel before ever turning it .

    Injection /ECU /manifold is there but not important for me , as i would run it with webers.....even delete the distributor as we use a dedicated ignition module with coilpack. We just need the crankshaft sensor.
     
  2. Keshav

    Keshav Well-Known Member Site Donor

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  3. Gransin

    Gransin Well-Known Member Site Donor

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    If you have an endoscope you can always inspect the cylinder walls through the spark plug holes.
    Mileage is as you say, all separate engines for sale are usually "low" mileage, but all old 535, 735 for sale usually has 200-300tkm+...
    I'd never pay over 4-500€ for an unknown mileage/condition M30B35.
     
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  4. Belgiumbarry

    Belgiumbarry Well-Known Member

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    Thanks Keshav, i just informed on your first offer mention… i asked the build year and when the engine was overhauled. I don't speak German besides a few words , so i cannot call.... he's 400 km from my home, so it should be possible to get that engine on a little trailer.....

    Now , when was the head changed to the safer design in water cooler passages ??? must look it up …
     
  5. Gransin

    Gransin Well-Known Member Site Donor

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    -82 and later:)
     
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  6. Keshav

    Keshav Well-Known Member Site Donor

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    Barry, if you need translations or questions related in German, feel free to let me know.

    The head change sounds like the M90 type but SFDon would be the right one for that question.
     
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  7. Belgiumbarry

    Belgiumbarry Well-Known Member

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    Robert , does that mean there are no "oem" engines with a distributor ignition with the "safe" heads ?
     
  8. sfdon

    sfdon Well-Known Member

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    Its a low horse power, low compression, short duration cam engine. Sold in the USA primarily.
    It was the answer for mid ‘80 smog laws.
    Change the pistons and cam and it’s great.
     
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  9. Belgiumbarry

    Belgiumbarry Well-Known Member

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    @sfdon , this is a europ engine... probably not the same as US versions…. i assume they were sold for 210 HP , 300 NM ???
     
  10. Gransin

    Gransin Well-Known Member Site Donor

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    You mean with the old style distributor? I'm not sure when they started with the newer style distributor on M30s, after -81?
    That might very well be the case. I bought an -82 stamped head and moved over all components from my early -71 head.
     
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  11. Bert Poliakoff

    Bert Poliakoff Active Member Site Donor

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    May of 81 was was first year of Motronic (Motronic Basic) and last year of the M90. Also, other than the infamous "L"under the intake manifold, it is hard to identify, as there isn't a raised water passage on the left side of the block.
     
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  12. sfdon

    sfdon Well-Known Member

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    Well
     
  13. sfdon

    sfdon Well-Known Member

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    Well maybe I should have paid attention to your handle!
    My apologies...
    If you are in Europe that should be , could be a 10:1
    compression high output engine.
    Take a look for vin stamping and let us know what it says.
     
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  14. Belgiumbarry

    Belgiumbarry Well-Known Member

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    yes Robert , i meant the old style distributor , so no ECU needed….i think all with injection ? were there even models with carbs but ECU ignition ?
     
  15. Gransin

    Gransin Well-Known Member Site Donor

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    I think -79 was the last year the M30 came with carbs, so no. Hope somebody chimes in if I'm wrong or have missed something.
     
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  16. Belgiumbarry

    Belgiumbarry Well-Known Member

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    @sfdon

    this is what the seller says :
    41633984
    34 6e c

    can't find that # on realoem… ??
     
  17. Belgiumbarry

    Belgiumbarry Well-Known Member

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    where is @sfdon when you need him :D

    ok, what i found :
    34 ( liters ) 6 ( cilinders) E ( injection) C (internal BMW code ,no importance i think ? )
    4 ( M30) 163 ( serial # ) 3 ( Munich factory) 984 ( production week )

    so no clue if it's the high compression engine... don't think you can see it on the outside.
     
  18. sfdon

    sfdon Well-Known Member

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    Through the spark plug hole we go......
     

    Attached Files:

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  19. Belgiumbarry

    Belgiumbarry Well-Known Member

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    @Gransin
    Robert , do you mean we can use a head with new style distributor ( the ones with injection and ECU ) and convert it to the old style distributor ?
    swapping the front plate and cam... i think ? or is there more involved ?
    If i would ever need the engine for the blue coupe i could do that and wouldn't need a ECU and coilpack…again $$$$ ( as on the rally car) , so that it also keeps the oem '70 look.
     
  20. Gransin

    Gransin Well-Known Member Site Donor

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    Yep, that's what I did. Cam and (cam gear?) + front plate should do it as far as I'm concerned, I also moved over the rocker arms to the same lobes they had previously been in contact with.
    Talking about M30 heads, one thing I wish I knew about before buying my newer head was the existense of the dimples:

    https://www.e9coupe.com/forum/threads/cylinder-head-and-cam-id.27528/
    https://www.e9coupe.com/forum/threads/wanted-cylinder-head-for-73-3-0cs.27977/#post-217261
    https://www.e9coupe.com/forum/threads/m90-cylinder-head-specs-help.28702/#post-225798
     
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